Posted by lostforwards on October 29, 2005, at 8:21:24
In reply to Re: grey matter, posted by alexandra_k on October 28, 2005, at 17:39:06
> > How thick is grey matter? I read somewhere that if forms the superficial parts of the brain but how thick is it?
>
>
> I might be wrong... But I think it might be about a centemeter or a little bit thicker in some places...
>
> The brain is kind of folded in on itself and the cortex (grey bit) follows the convolutions in the brain. I'll see if I can find a pic...
>
> http://webvision.med.utah.edu/imageswv/FIG5VisualCortex.jpg
>
> The darker bits are the grey bits.
>
> It forms the 'superficial parts' in the sense that it comprises the outside layer of the brain. They thought it was like bark and I think thats how it got the name 'cortex'. Though I'm not quite sure that that is right....
>
> It is grey because it has a lot of brain cells. The body of the cells are grey and thats why it looks grey.
>
> Under the cortex there is a lot of white... The brain cells have axons (like a tree trunk) that branch into connections with other brain cells. The axons are typically coated in myelin (to protect it and make communication between neurons faster). Myelin is white and so thats why the inner bits are white rather than grey.
>
> Its been a while, but I think this is right...That's perfect. Thanks.
poster:lostforwards
thread:572756
URL: http://www.dr-bob.org/babble/social/20051029/msgs/572997.html